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STRCPY(3) DragonFly Library Functions Manual STRCPY(3)
strcpy, strncpy -- copy strings
Standard C Library (libc, -lc)
stpcpy(char *dst, const char *src);
stpncpy(char * restrict dst, const char * restrict src, size_t len);
strcpy(char * restrict dst, const char * restrict src);
strncpy(char * restrict dst, const char * restrict src, size_t len);
The stpcpy() and strcpy() functions copy the string src to dst (including
the terminating `\0' character.)
The stpncpy() and strncpy() functions copy at most len characters from
src into dst. If src is less than len characters long, the remainder of
dst is filled with `\0' characters. Otherwise, dst is not terminated.
The strcpy() and strncpy() functions return dst. The stpcpy() and
stpncpy() functions return a pointer to the terminating `\0' character of
dst. If stpncpy() does not null-terminate dst because the length of src
was greater than len, then it returns a pointer to dst[len], which may
not be valid.
The following sets chararray to ``abc\0\0\0'':
(void)strncpy(chararray, "abc", sizeof(chararray));
The following sets chararray to ``abcdef'':
(void)strncpy(chararray, "abcdefgh", sizeof(chararray));
Note that it does not NUL terminate chararray because the length of the
source string is greater than or equal to the length argument.
The following copies as many characters from input to buf as will fit and
NUL terminates the result. Because strncpy() does not guarantee to NUL
terminate the string itself, this must be done explicitly.
(void)strncpy(buf, input, sizeof(buf) - 1);
buf[sizeof(buf) - 1] = '\0';
This could be better achieved using strlcpy(3), as shown in the following
(void)strlcpy(buf, input, sizeof(buf));
Note that because strlcpy(3) is not defined in any standards, it should
only be used when portability is not a concern.
The strcpy() function is easily misused in a manner which enables mali-
cious users to arbitrarily change a running program's functionality
through a buffer overflow attack. (See the FSA and EXAMPLES.)
bcopy(3), memccpy(3), memcpy(3), memmove(3), strlcpy(3)
The strcpy() and strncpy() functions conform to ISO/IEC 9899:1990
(``ISO C90''). The stpcpy() and stpncpy() functions conform to IEEE Std
The stpcpy() function first appeared in FreeBSD 4.4, coming from
1998-vintage Linux and stpncpy() first appeared in DragonFly 2.13.
DragonFly 3.5 January 20, 2012 DragonFly 3.5